Multiplexing Filter Circuit with Shared Ports

1 . An apparatus comprising:

at least one multiplexing filter circuit comprising multiple filters, each respective filter of the multiple filters having a respective distinct passband that corresponds to a frequency band, the multiple filters comprising a first group of filters and a second group of filters that is different from the first group of filters;

a first plurality of nodes coupled between the multiple filters and at least one antenna port, the first plurality of nodes comprising a first node coupled between the first group of filters and the at least one antenna port; and

a second plurality of nodes coupled between the multiple filters and processing circuitry, the second plurality of nodes comprising a first node coupled between the second group of filters and the processing circuitry,

the first group of filters and the second group of filters each comprising at least one filter of the multiple filters in common.

2 . The apparatus of claim 1 , wherein:

the multiple filters comprise a first filter, a second filter, and a third filter;

the first group of filters comprises the first filter and the second filter; and

the second group of filters comprises the second filter and the third filter.

3 . The apparatus of claim 2 , wherein:

the multiple filters comprise a fourth filter, a third group of filters, and a fourth group of filters;

the third group of filters comprises the third filter and the fourth filter; and

the fourth group of filters comprises the first filter and the fourth filter.

4 . The apparatus of claim 3 , wherein:

a second node of the first plurality of nodes is coupled between the third group of filters and the at least one antenna port; and

a second node of the second plurality of nodes is coupled between the fourth group of filters and the processing circuitry.

5 . The apparatus of claim 4 , wherein:

the processing circuitry comprises multiple amplifiers, including a first amplifier and a second amplifier;

the first amplifier is coupled to the first node of the second plurality of nodes; and

the second amplifier is coupled to the second node of the second plurality of nodes.

6 . The apparatus of claim 5 , wherein:

the first amplifier comprises a first low-noise amplifier, and the second amplifier comprises a second low-noise amplifier;

an input of the first low-noise amplifier is coupled to the first node of the second plurality of nodes; and

an input of the second low-noise amplifier is coupled to the second node of the second plurality of nodes.

7 . The apparatus of claim 5 , wherein:

the first amplifier comprises a first power amplifier, and the second amplifier comprises a second power amplifier;

an output of the first power amplifier is coupled to the first node of the second plurality of nodes; and

an output of the second power amplifier is coupled to the second node of the second plurality of nodes.

8 . The apparatus of claim 3 , wherein:

the first group of filters comprises a first diplexer;

the second group of filters comprises a second diplexer;

the third group of filters comprises a third diplexer; and

the fourth group of filters comprises a fourth diplexer.

9 . The apparatus of claim 1 , wherein:

the first group of filters comprises a first n-plexer;

the second group of filters comprises a second n-plexer; and

the at least one filter of the multiple filters is part of the first n-plexer and part of the second n-plexer.

10 . The apparatus of claim 1 , wherein:

the first group of filters is defined relative to an antenna side of the at least one multiplexing circuit, the antenna side corresponding to the first plurality of nodes and the at least one antenna port; and

the second group of filters is defined relative to a processing side of the at least one multiplexing circuit, the processing side corresponding to the second plurality of nodes and the processing circuitry.

11 . An apparatus comprising:

a first filter and a second filter each coupled to a first common input port that is common to the first filter and the second filter, the first filter comprising a first filter output, and the second filter comprising a second filter output;

a third filter and a fourth filter each coupled to a second common input port that is common to the third filter and the fourth filter, the third filter comprising a third filter output coupled to the second filter output to form a first common output port, and the fourth filter comprising a fourth filter output coupled to the first filter output to form a second common output port;

a first low-noise amplifier comprising an input coupled to the first common output port;

a second low-noise amplifier comprising an input coupled to the second common output port; and

a switching circuit comprising a switch input, a first switch output coupled to the first common input port, and a second switch output coupled to the second common input port, the switching circuit configured to selectively couple the switch input to the first switch output and the second switch output.

12 . The apparatus of claim 11 , wherein:

a first filter response of the first filter corresponds to a first frequency band, and a second filter response of the second filter corresponds to a second frequency band;

the first frequency band and the second frequency band correspond to a first active carrier aggregation combination;

a third filter response of the third filter corresponds to a third frequency band, and a fourth filter response of the fourth filter corresponds to a fourth frequency band; and

the third frequency band and the fourth frequency band correspond to a second active carrier aggregation combination different from the first active carrier aggregation combination.

13 . The apparatus of claim 12 , wherein:

the second frequency band and the third frequency band are nonadjacent to each other; and

the first frequency band and the fourth frequency band are nonadjacent to each other.

14 . The apparatus of claim 12 , wherein:

the first active carrier aggregation combination is active at a first time; and

the second active carrier aggregation combination is active at a second time different from the first time.

15 . The apparatus of claim 11 , wherein:

at least one of the second filter or the third filter has one or more characteristics configured to reduce an impact of loading of the third filter on the second filter while the second filter is actively filtering a signal.

16 . The apparatus of claim 15 , wherein:

a passband of the second filter is nonoverlapping with a passband of the third filter.

17 . The apparatus of claim 11 , wherein:

an impedance component is coupled between the first common output port and a ground.

18 . The apparatus of claim 17 , wherein:

the impedance component comprises at least one of an inductor or a capacitor.

19 . A method comprising:

propagating a first signal through a first common input port;

filtering the first signal with a first filter to produce a first filtered signal;

filtering the first signal with a second filter to produce a second filtered signal;

routing the first filtered signal to a first common output port;

routing the second filtered signal to a second common output port;

propagating a second signal through a second common input port;

filtering the second signal with a third filter to produce a third filtered signal;

filtering the second signal with a fourth filter to produce a fourth filtered signal;

routing the third filtered signal to the second common output port; and

routing the fourth filtered signal to the first common output port.

20 . The method of claim 19 , further comprising:

after the routing of the first filtered signal to the first common output port, low-noise amplifying the first filtered signal; and

after the routing of the second filtered signal to the second common output port, low-noise amplifying the second filtered signal.